<div id='file_browse_wrapper'>
  <input class="iconos" type="file" name="File Upload" id='file_browse' accept=".csv" />
</div>
  <label id="url-archivo"><b>Selecciona tu archivo...</b></label>
  <button class="btn btn-success" id="carga-archivo">Subir</button>

$("#carga-archivo").click(function () {
                    var fileUpload = document.getElementById("file_browse");
                    if (fileUpload .value != null) {
                        var uploadFile = new FormData();
                        var files = $("#file_browse").get(0).files;
                        // Add the uploaded file content to the form data collection
                        if (files.length > 0) {
                            uploadFile.append('file-'+i, file);
                            $.ajax({
                                url: "/2/delivery/client/massive",
                                contentType: false,
                                processData: false,
                                data: uploadFile,
                                type: 'POST',
                                success: function () {
                                   alert("file upload successfuly");
                                }
                            });
                        }
                    }
                });